Dolphin deaths could rapidly decrease if Greenpeace and the Whales and Dolphin Society have their way.
The conservation groups say that harmful fishing methods could lead to some species becomming extinct.
A report published on Tuesday called The Net Effect? thinks that about 10,000 of the mammals die every year around the coasts of the UK and France.
On the 21st January the Greenpeace vessel, the Esperanza, will sail from London to spend six weeks in the English Channel, the Celtic Sea and the Bay of Biscay.